1. Field of the Invention
In general, the present invention relates to connectors that are used to terminate electrical ribbon cables. More particularly, the present invention relates to the structure of ribbon cable connectors and the manner in which such connectors create electrical contact with ribbon cables.
2. Prior Art Description
Ribbon connectors are used in many electronic devices, such as computers, scanners, printers and the like. Ribbon cables are cables where all the wires of the cable are aligned in parallel in a flat ribbon. Ribbon cables typically contain wires between 22 AWG and 26 AWG. A ribbon cable can contain up to eighty individual wires. However, most common ribbon cables contain between twelve and thirty individual wires.
Since a ribbon cable contains so many small individual wires, it is difficult to terminate ribbon cables correctly. If just one wire within the ribbon cable is not contacted properly within a connector, then the ribbon cable installation fails. Obviously, the difficultly in terminating ribbon cables is directly proportional to the gauge of the wires and the number of wires in the ribbon cables. In modern electronics, the wires are becoming increasingly thin. Likewise, the number of wires being used in ribbon cables is increasing. Accordingly, the difficulties of terminating ribbon cables is currently increasing.
Another problem associated with terminating ribbon cables is one of wire/contact misalignment. When a ribbon cable is terminated within a ribbon connector, each of the wires of the ribbon cable is brought into contact with some form of electrical contact. As wires become smaller and denser, so do the corresponding contacts within the connector. The density of the wires and contacts requires that a ribbon cable be precisely aligned within a connector. If the ribbon cable moves and becomes slightly askew, a wire from the ribbon cable may touch the wrong contact within the connector. The result is an electrical short.
In the prior art, the problems of creating a quality connection between a connector and a ribbon cable have been attempted in many ways. In many prior art connectors, pins are used to pierce the ribbon cable and contact the various wires. Such connectors are commonly referred to as insulation displacement connectors (IDC Connectors) such as the BT224 connector, as defined by BS9525-F0023, DIN41651, MIL-C-83503 standards.
Connectors that require that ribbon cables be pierced are very difficult to use with wide, high-density ribbon cables. As such, other approaches have been tried. One approach is to provide two off-set contacts for each wire within the connector. In this manner, the wires in a ribbon cable will only contact both of its contacts if that wire is properly aligned. Such prior art ribbon cable connectors are exemplified by U.S. Pat. No. 6,273,747 to Helfrich, entitled Connector For A Flat Flexible Cable.
The problem associated with such prior art connectors is that the connector merely provides a way to check if a ribbon cable is properly oriented. The connector does nothing to reduce the need for the ribbon cable to be properly oriented. As such, the same connections problems exist, those problems are only now more detectable.
A need therefore exists for a ribbon cable connector that is capable of creating a consistent, quality connection with a ribbon cable while simultaniously reducing the precision needed in placing the ribbon cable into the connector. These needs are met by the present invention as described and claimed below.